Projectile parameters are positive scale factors, best adjusted
multiplicatively. Replace the input boxes with logarithmic sliders
spanning 0.1x to 10x the seeded default, which sits at the geometric
midpoint of the range; mass spans 0.1x to 100x since heavy projectiles
are a common want. Ctrl+Click still allows typing values outside the
slider range, and each slider gets a reset button restoring its
default. Adds an ImGui_SliderLog widget operating on mjtNum.
PiperOrigin-RevId: 957071873
Change-Id: Id46eae28f73308d98681ccbeb2764c949f98f9d9
Yuval Tassa
e9197e1e9d